NASA approved two probes for the Mariner-Mars 1964 project in November 1962.

The primary goal of the two spacecraft was to photograph the Martian surface using a single TV camera fixed on a scan platform that could return up to twenty-one pictures after an eight-month journey.

During the launch of Mariner 3, the first of the two probes, the booster payload shroud failed to separate from the payload. Additionally, battery power mysteriously dropped to zero (at T+8 hours 43 minutes), and the spacecraft's solar panels apparently never unfurled to replenish the power supply. As a result, ground control lost contact with the spacecraft, which eventually entered heliocentric orbit.

A later investigation indicated that the shroud's inner fiberglass layer had separated from the shroud's outer skin, thus preventing jettisoning.

Key Dates

5 Nov 1964: Launch

6 Nov 1964: End of Mars Mission

Status: Unsuccessful

Fast Facts

Mariner 4 was equipped to snap only 21 pictures during its planned Mars flyby.

Its journey to Mars was to take about eight months.

Electrical power for all experiments and spacecraft functions was provided by 28,244 solar cells mounted on four collapsed panels designed to deploy in flight.